This invention relates to a servo-steering system for automotive vehicles within which a vehicle speed dependent feedback force is developed to resist the manual steering effort applied, and is related to the invention disclosed and claimed in my copending application, Ser. No. 379,455 filed May 18, 1982.
Powered steering systems wherein the degree of fluid feedback developed is varied, are already known as discussed in my aforementioned copending application. As indicated in the aforementioned copending application, prior art power steering arrangements include flow controlling valve pistons which act as reaction pistons and may be unintentionally displaced as a result of malfunction. Further, any failure in the reaction or feedback pressure regulating means prevents control valve operation with any feedback characteristics.
It is therefore an object of the present invention to provide a servo-steering system with a vehicle speed controlled feedback that avoids the disadvantages of comparable prior art arrangements and wherein movement of the control valve is always constrained even in the event of failure of the regulating facilities for feedback forces.